Inflammation & Repair

Question 1

What form of cell death causes an inflammatory response?

Answer 1

Necrosis

Question 2

Three features of acute inflammation?

Answer 2

1. Dilation & hyperaemia
2. Oedema exudate
3. Leukocyte…Neutropils recruitment & activation

Question 3

five signs of acute inflammation

Answer 3

1. Heat - hyperaemia
2. redness - hyperaemia
3. swelling - oedema due to hyperaemia & increased permeability
4. pain - stretch receptors & chemical mediators
5. loss of function - swelling & pain

Question 4

three possible outcomes of acute inflammation?

Answer 4

1. Resolution
2. organization
3. chronic inflammation

Question 5

three main components of granulation tissue & their role/purpose in repair

Answer 5

1. fibroblasts: secrete collagen proteins
2. Macrophages: coordinate events & clean up debris
3. Angiogenesis: the formation of new blood vessels to provide nutrients and blood gases during the repair process

Question 6

Consequences of healing through organization

Answer 6

Scarring allows repair & fills in the tissue deficits so we can survive but it lacks the properties of the tissue that it replaces reducing function reserve.

Question 7

What are the three main causes of chronic inflammation

Answer 7

1. repeated acute inflammation
2. unresolved acute when the stimulus causing the acute response remains
3. special cases

Question 8

three general features of chronic inflammation

Answer 8

1. ongoing tissue injury and destruction
2. lymphocytes
3. repeated attempts at repair through the formulation of granulation tissue and , when occurring in stable/labile tissues, proliferation of parenchymal cells

Question 9

possible negative consequences of chronic inflammation

Answer 9

A lot more tissue destruction and scarring, a lot more loss of functional of tissue. If there is epithelial tissue, there will be an increased risk of cancer

Question 10

Non-Sterile sites in the body

Answer 10

should have microorganisms:

skin, GIT, upper respiratory, lower urogenital

Question 11

Sterile sites in the body

Answer 11

shouldn’t have microorganisms:

blood, brain & CSF, bone & marrow, lower respiratory, upper urogenital

Question 12

Innate Response:

Answer 12

• fast
• not specific
• germ-line encoded
• cellular: neutrophils, macrophages, NK cells
• Humoral: complement components

Question 13

Acquired Response:

Answer 13

• slow
• able to differentiate between targets
• learns & remembers ‘memory’
• Cellular: T & B Cells
• Humoral: Antibodies

Question 14

Autoimmune Response

Answer 14

Immune system targeting itself without a stimulus

Question 15

Hypersensitivity Response

Answer 15

Overreaction to stimulus

Question 16

when can acute inflammation be life-threatening?

Answer 16

The brain, lungs & throat, lungs, pericardium, pleura & peritoneum

Question 17

What type of oedema is observed in acute inflammation and how does it occur?

Answer 17

Exudate, which is an oedematous fluid which is high in proteins. hyperaemia results in increased hydrostatic pressure which forces fluid from the vessels into the tissue (transudate) but there is also increased vascular permeability which allows plasma proteins to also enter the fluid hence why we get an exudate.

Question 18

What factors may prevent complete repair from occurring?

Answer 18

Permanent tissues like the brain and heart will never heal by resolution as neurons. In labile/stable tissues resolution is not possible when a lot of tissue has been lost or when there is overlying infection, poor immunity, poor nutrition, or interruption of healing

Question 19

Under what circumstances does granulation tissue occur?

Answer 19

Granulation tissue is the immature scar, the tissue that forms the scar and so will occur in acute inflammation that heals through organization, and it will always be present in chronic inflammation as part of the repeated attempts at repair

Question 20

what happens to the heart in response to ischemia?

Answer 20

The heart tissue affected by ischemia would have survived using anaerobic metabolism for a short period of time before succumbing to necrosis. The infarcted tissue would stimulate the acute inflammatory response……

Question 21

Transition from acute to chronic inflammation

Answer 21

If there is little pain perceived and function is unimpaired, acute inflammation within an internal organ may elicit no or only subtle clinical symptoms. Without overt symptoms alerting to the presence of pathology treatment may not be administered and an acute inflammatory response may become chronic. Chronic inflammation may also occur when the immune system fails to distinguish self from non-self and in response to some infections

Question 22

In most of the specimens the process of chronic inflammation is ongoing because the cause persists. If the cause of the chronic inflammation had been treated, what would have happened?

Answer 22

The granulation tissue would have matured into scar tissue as happens with organization.

Question 23

How can chronic inflammation lead to cancer?

Answer 23

increased proliferation of epithelial cells and oxidative stress because of chronic inflammation has led to the development of cancer. it is NOT the inflammatory cells ) that give rise to cancer but the surrounding epithelium.

Question 24

following a myocardial infarction what type of inflammation and repair occurs?

Answer 24

inflammation = acute
repair = organization

Question 25

Why does chronic inflammation increase the risk of carcinoma formation?

Answer 25

When chronic inflammation occurs in stable or labile tissues that contain epithelial cells, surrounding epithelial cells will proliferate (undergo hyperplasia) in a futile attempt to repair. This increase in proliferation & the presence of free radicals increases the chance of mutation. Note that it is not the granulation tissue that causes cancer & repair does not necessarily involve cell division

Question 26

what is the mature scar tissue made our ot (apart from in the brain)

Answer 26

collagen protein (in the brain it is glial)